Active Eco, engaged by a dashboard switch to the left of the steering
wheel, modifies engine operation so you get more gradual acceleration,
and the transmission tends to shift to higher gears sooner and isn’t as
quick to downshift for passing. Active Eco also cuts off the fuel supply
during deceleration, and Hyundai says all this electronic management
can increase fuel economy as much as 7 percent.

I would like to know what the engine actually does when the system is operating? Is it only meant for city driving usage? Does it make sense to use it during highway driving or when the air conditio...